Xinshengin, the first altenusin with tetracyclic skeleton core from Phialophora spp.

Xinshengin (1), the first tetracyclic altenusin with an unprecedented altenuene/tetrahydrofuran-fused skeleton core, has been obtained from cultures of an endolichenic fungal strain Phialophora spp. (No. 39-1-5-1), along with a new compound, phialophoriol (2), and a known compound, altenusin (3). The structures with absolute configurations of 1 and 2 were elucidated by analysis of NMR and quantum chemical ECD calculation.